recF and recR are required for the resumption of replication at DNA replication forks in Escherichia coli
AUTOR(ES)
Courcelle, Justin
FONTE
The National Academy of Sciences of the USA
RESUMO
Escherichia coli containing a mutation in recF are hypersensitive to UV. However, they exhibit normal levels of conjugational or transductional recombination unless the major pathway (recBC) is defective. This implies that the UV sensitivity of recF mutants is not due to a defect in recombination such as occurs during conjugation or transduction. Here, we show that when replication is disrupted, at least two genes in the recF pathway, recF and recR, are required for the resumption of replication at DNA replication forks, and that in their absence, localized degradation occurs at the replication forks. Our observations support a model in which recF and recR are required to reassemble a replication holoenzyme at the site of a DNA replication fork. These results, when taken together with previous literature, suggest that the UV hypersensitivity of recF cells is due to an inability to resume replication at disrupted replication forks rather than to a defect in recombination. Current biochemical and genetic data on the conditions under which recF-mediated recombination occurs suggest that the recombinational intermediate also may mimic the structure of a disrupted replication fork.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=20506Documentos Relacionados
- Involvement of recF, recO, and recR Genes in UV-Radiation Mutagenesis of Escherichia coli
- Biochemical interaction of the Escherichia coli RecF, RecO, and RecR proteins with RecA protein and single-stranded DNA binding protein.
- Interactions of RecF protein with RecO, RecR, and single-stranded DNA binding proteins reveal roles for the RecF–RecO–RecR complex in DNA repair and recombination
- Mutation of recF, recJ, recO, recQ, or recR improves Hfr recombination in resolvase-deficient ruv recG strains of Escherichia coli.
- The phage lambda orf gene encodes a trans-acting factor that suppresses Escherichia coli recO, recR, and recF mutations for recombination of lambda but not of E. coli.